In 1907 he purchased the Daily News and the Evening Herald and consolidated them into the Daily News-Herald. He was a member of the Pennsylvania House of Representatives from 1910 to 1913.

Kelly was elected as a Republican to the Sixty-third Congress, but was an unsuccessful candidate in 1914. After his term in Congress, he continued his newspaper work. He was again elected as a Progressive to the Sixty-fifth and reelected as a Republican to the eight succeeding Congresses. He was an unsuccessful candidate for reelection in 1934.

During his tenure as Congressman, Clyde introduced a resolution to permit private contracting of airmail service. This resolution, the Airmail Act of 1925 was signed into law on February 2, 1925, prompting many companies to venture into the aviation field (e.g., Boeing, Douglas, and Pratt & Whitney). The Airmail Act of 1925 was the foundation that commercial aviation is built upon.[1]